JP7099079B2 - Paper transfer device - Google Patents

Description

The present invention relates to a paper transport device that detects double feeding of paper using an ultrasonic sensor.

There is a device that transports paper and executes jobs. As such an apparatus, for example, there is an image forming apparatus. The image forming apparatus is, for example, a multifunction device, a printer, a copying machine, or a fax machine. Then, a plurality of sheets of paper may be overlapped and conveyed (double feeding). Double feeding of paper can cause paper jams. In addition, the content of one page may be printed on a plurality of sheets. In this way, when double feeding occurs, printing may not be performed properly. Patent Document 1 describes an example of a technique for detecting double feeding of paper.

Specifically, in Patent Document 1, an ultrasonic wave is transmitted, a transmitted ultrasonic signal is received, a sheet is conveyed between the transmitted ultrasonic waves, and the sheet passes between the ultrasonic waves. Based on the reception level of the ultrasonic signal received in the meantime, the double feed detection in which multiple sheets are overlapped and conveyed is detected, the double feed detection is executed multiple times, and the double feed detection executed multiple times is performed. The last double feed detection is executed in the upstream end section in the paper transport direction, which is the section from the upstream end of the sheet in the paper transport direction to the position separated by a predetermined distance in the sheet transport direction. A sheet transfer device that controls the execution timing of double feed detection is described. In Patent Document 1, the reception level of the ultrasonic signal is not confirmed within a range including the upstream end portion in the sheet paper transport direction (Patent Document 1: Claim 1, paragraph [0017]).

JP-A-2017-030881

An ultrasonic sensor may be used to detect double feed of paper. The ultrasonic sensor includes a transmitting circuit and a receiving circuit. The transmission circuit emits ultrasonic waves. The receiving circuit outputs a voltage according to the level of the received ultrasonic wave. Paper passes between the transmitting circuit and the receiving circuit. When double feeding occurs, the amount (intensity) of ultrasonic waves received by the receiving circuit is lower than when double feeding does not occur. When double feed occurs, the output level of the receiving circuit drops. Based on the output level of the receiving circuit, it is determined whether or not double feeding has occurred.

Here, vibration (impact) may be applied to the paper while the paper is passing between the transmission circuit and the reception circuit. Vibrations can cancel the ultrasound. Even if only one sheet of paper is conveyed, the output level of the receiving circuit may temporarily decrease due to the vibration applied to the paper. There is a problem that it may be erroneously detected that double feeding has occurred due to the vibration applied to the paper.

Patent Document 1 does not describe the vibration applied to the paper. It is not possible to deal with false detection of double feeding due to vibration of paper. Therefore, the technique described in Patent Document 1 cannot solve the above problem.

In the present invention, in view of the above problems, the vibration applied to the paper is taken into consideration, and it is determined whether or not the double feed has occurred accurately.

The paper transport device according to the present invention includes a paper feed unit, a rotating body for transport, a transport guide, a double feed detection unit, and a control unit. The paper feed unit accommodates the paper and supplies the paper. The transport rotating body transports paper. The transport guide guides the transport paper. The double feed detection unit includes an ultrasonic sensor and a charge circuit. A detection voltage, which is an output of the double feed detection unit, is input to the control unit. The ultrasonic sensor includes a transmitting unit and a receiving unit. The transmitter transmits ultrasonic waves. The receiving unit outputs an electric charge according to the level of the received ultrasonic wave. The transmitting unit and the receiving unit are provided on the paper transport path and so that the paper is transported between them. The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage. The control unit sets a detection section for transmitting ultrasonic waves to the transmission unit for each transfer paper. In the detection section, the control unit transmits ultrasonic waves having a predetermined cycle to the transmission unit. The control unit sets a detection execution section and a detection skip section within the detection section. The control unit determines whether or not double feeding occurs in the detection execution section based on the detection voltage. The control unit does not determine whether or not double feed has occurred in the detection skip section based on the detection voltage. The control unit sets the detection skip section based on the time when vibration is applied to the transport paper.

According to the present invention, it is possible to accurately determine whether or not double feeding has occurred while considering the vibration applied to the paper.

It is explanatory drawing which shows an example of the image forming apparatus which concerns on embodiment. It is a figure which shows an example of the part about the paper transport in the multifunction device which concerns on embodiment. It is a figure which shows an example of the part about the paper transport in the multifunction device which concerns on embodiment. It is a figure which shows an example of the double feed detection processing of the multifunction device which concerns on embodiment. It is a figure which shows an example of the classification table of the type of the paper in the multifunction device which concerns on embodiment. It is a figure which shows an example of the section setting in the double feed detection processing which concerns on embodiment. It is a figure which shows an example of the processing in the detection execution section which concerns on embodiment. It is a figure which shows an example of the collision of the tip of the paper in the multifunction device which concerns on embodiment. It is a figure which shows an example of the collision of the tip of the paper in the multifunction device which concerns on embodiment. It is a figure which shows an example of the collision of the tip of the paper in the multifunction device which concerns on embodiment. It is a figure which shows an example of the collision of the rear end of the paper in the multifunction device which concerns on embodiment. It is a figure which shows an example of setting of the detection skip section which concerns on embodiment. It is a figure which shows an example of setting of the detection skip section which concerns on embodiment. It is a figure which shows an example of setting of the detection skip section which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9. In this description, the multifunction device 100 will be described as an example of the paper transport device. The multifunction device 100 conveys and prints paper. The multifunction device 100 is also an image forming apparatus. Hereinafter, each element such as the configuration and arrangement described in the description of the present embodiment does not limit the scope of the invention and is merely an explanatory example.

(Multifunction device 100)
First, an example of the multifunction device 100 according to the embodiment will be described with reference to FIG. FIG. 1 is an explanatory diagram showing an example of an image forming apparatus according to an embodiment.

As shown in FIG. 1, the multifunction device 100 includes a control unit 1 and a storage unit 2. The control unit 1 controls each unit of the multifunction device 100. The control unit 1 includes a control circuit 10 and an image processing circuit 11. The control circuit 10 is, for example, a CPU. The control circuit 10 performs operations and processes related to control. The image processing circuit 11 processes image data. The storage unit 2 includes a storage device such as a ROM, a RAM, and an HDD. The storage unit 2 stores a control program and various data.

The multifunction device 100 includes an image reading unit 3. The image reading unit 3 reads the set document. The image reading unit 3 generates image data of the original. The image data of the manuscript is used as image data for printing.

The multifunction device 100 includes an operation panel 4. The control unit 1 is communicably connected to the operation panel 4. The operation panel 4 includes a display panel 41, a touch panel 42, and a hard key 43 (for example, a start key). The control unit 1 controls the display of the display panel 41. The control unit 1 displays a screen and an image on the display panel 41. For example, the control unit 1 displays an operation image. The operation image is, for example, a soft key or a button. Based on the output of the touch panel 42, the control unit 1 recognizes the operated operation image. Further, the control unit 1 recognizes the operated hard key 43. In this way, the operation panel 4 accepts the user's operation. The control unit 1 recognizes the content of the setting operation performed on the operation panel 4. Further, the control unit 1 causes the display panel 41 to switch the display contents according to the operated operation image and the hard key 43. The control unit 1 controls the multifunction device 100 so that it operates as set.

Further, the multifunction device 100 includes a printing unit 5. The printing unit 5 includes a paper feeding unit 6, a paper transport unit 7, an image forming unit 8a, and a fixing unit 8b. At the time of a print job, the control unit 1 supplies the paper to the paper feed unit 6 one by one. The control unit 1 causes the paper transport unit 7 to transport paper. The control unit 1 causes the image forming unit 8a to form a toner image based on the image data for printing by using the toner. The control unit 1 causes the image forming unit 8a to transfer the toner image to the transport paper. The control unit 1 causes the fixing unit 8b to fix the toner image on the paper. The paper transport unit 7 ejects the printed paper to the ejection tray.

The multifunction device 100 includes a communication unit 13. The communication unit 13 communicates with the computer 200. The computer 200 is, for example, a PC or a server. The communication unit 13 includes a connector for communication and a communication circuit. The communication unit 13 can send and receive data to and from the computer 200.

(Paper transfer)
Next, an example of a part related to paper transport in the multifunction device 100 according to the embodiment will be described with reference to FIGS. 2 and 3. 2 and 3 are diagrams showing an example of a portion related to paper transport in the multifunction device 100 according to the embodiment.

The multifunction device 100 includes a paper feeding unit 6 and a paper conveying unit 7. As shown in FIG. 2, the paper feed unit 6 includes a paper cassette 61, a paper feed motor 62, and a paper feed rotating body 63 (pickup roller). The paper cassette 61 accommodates a bundle of paper. The paper feed rotating body 63 is in contact with the stored paper. The paper feed rotating body 63 is rotated by the drive of the paper feed motor 62. Paper is fed from the paper cassette 61 by the rotation of the paper feed rotating body 63. At the time of a print job, the control unit 1 rotates the paper feed motor 62. When printing a plurality of sheets in succession, the control unit 1 repeatedly rotates and pauses the paper feed motor 62 to provide a predetermined space between the sheets.

The paper sent out from the paper feed unit 6 enters the paper transport unit 7. As shown in FIG. 3, the paper transport unit 7 includes a transport rotating body 71 and a transport guide 74. The transport rotating body 71 rotates to transport the paper. The transport guide 74 guides the transport paper. FIG. 3 shows an example of a portion of the paper transport unit 7 that is conveyed from the lower side (feeding unit 6) to the upper side (image forming unit 8a). In FIG. 3, the lower transport rotating body 71 is an intermediate roller pair 72. In FIG. 3, the upper rotating body 71 for transport is a resist roller pair 73.

The paper transport unit 7 includes one or more transport motors 70. In the transfer motor 70, one or a plurality of transfer rotating bodies 71 are rotated by the drive of the transfer motor 70. Paper is conveyed by the rotation of the conveying rotating body 71. The paper passes through the transport path by the transport guide 74. At the time of the print job, the control unit 1 rotates the conveyor motor 70.

(Double feed detection unit 9)
Next, an example of the double feed detection unit 9 included in the multifunction device 100 according to the embodiment will be described with reference to FIGS. 2 and 3.

Double feeding (transportation in which multiple sheets of paper are overlapped) may occur. For example, a part of the next paper may be overlapped with a part of the preceding paper and conveyed. For example, double feeding may occur due to continuous paper feeding. In some cases, two sheets of paper may be transported on top of each other almost completely.

Paper jams may occur due to double feeding. Further, when the paper reaches the image forming unit 8a in the double feed state, the content of one page is printed over a plurality of sheets of paper. Useless printing will be performed. When double feeding occurs, the transport rotating body 71 (conveying motor 70) should be stopped promptly. Therefore, in order to detect the double feed, the multifunction device 100 includes the double feed detection unit 9.

The double feed detection unit 9 includes an ultrasonic sensor 91, a charge circuit 94, and a switch unit 95. The ultrasonic sensor 91 includes a transmitting unit 92 and a receiving unit 93. The transmitting unit 92 and the receiving unit 93 include a piezoelectric element. When performing double feed detection, the control unit 1 inputs a pulse having a predetermined period (frequency) to the transmission unit 92. For example, a pulse of about several tens to several hundreds of Hz is input to the transmission unit 92. The piezoelectric element is deformed by applying a voltage (pulse). As a result, the transmission unit 92 can transmit ultrasonic waves having the frequency of the input pulse.

The receiving unit 93 receives the ultrasonic waves radiated from the transmitting unit 92. The piezoelectric element of the receiving unit 93 outputs a charge (voltage) corresponding to the strength (sound pressure) of the ultrasonic pressure. The receiving unit 93 may include an amplifier circuit that amplifies the output of the piezoelectric element. In other words, the receiving unit 93 may output a voltage (charge) that amplifies the output of the piezoelectric element.

As shown in FIG. 3, the transmitting unit 92 and the receiving unit 93 are provided so as to sandwich the transport paper. The ultrasonic wave transmitting surface of the transmitting unit 92 and the ultrasonic wave receiving surface of the receiving unit 93 face each other. Paper passes between the transmitting unit 92 and the receiving unit 93. In order to stop the paper transport before the transfer of the toner image (before the arrival of the image forming portion 8a), the ultrasonic sensor 91 is provided on the upstream side in the paper transport direction with respect to the image forming portion 8a. FIG. 3 shows an example in which the ultrasonic sensor 91 is provided between the paper feeding unit 6 and the image forming unit 8a in the paper transport path.

The charge circuit 94 is a circuit for charging the output (charge) of the receiving unit 93. The charge circuit 94 includes a capacitor. The capacitor charges the charge. During charging, each time the receiving unit 93 receives an ultrasonic wave and outputs a pulse, the voltage between the terminals of the capacitor increases. A voltage based on the electric charge stored in the capacitor (voltage of the input side terminal of the capacitor) is input to the control unit 1 as a detection voltage V1.

The control unit 1 A / D-converts the input detection voltage V1 and recognizes the magnitude of the detection voltage V1. An A / D conversion circuit may be provided in the double feed detection unit 9, and the A / D conversion circuit may generate digital data indicating the magnitude of the detection voltage V1. In this case, the digital data generated by the A / D conversion circuit is input to the control unit 1. The control unit 1 recognizes the magnitude of the detection voltage V1 based on the input digital data.

A switch section 95 is provided for the charge circuit 94. The switch unit 95 is a switch for removing the electric charge of the charge circuit 94. The control unit 1 controls ON / OFF of the switch unit 95. When the charge of the charge circuit 94 is removed, the control unit 1 turns on the switch unit 95. For example, when the switch unit 95 is turned on, a capacitor (the terminal of the capacitor that receives the output of the receiving unit 93) is connected to the ground. As a result, discharge is performed. When charging the charge circuit 94, the control unit 1 turns off the switch unit 95. For example, when the switch unit 95 is turned off, the connection between the capacitor (the terminal of the capacitor that receives the output of the receiving unit 93) and the ground is released. As a result, charging is performed.

(Flow of double feed detection processing)
Next, an example of the double feed detection process of the multifunction device 100 according to the embodiment will be described with reference to FIGS. 4 to 7. FIG. 4 is a diagram showing an example of double feed detection processing of the multifunction device 100 according to the embodiment. FIG. 5 is a diagram showing an example of a paper type classification table L1 in the multifunction device 100 according to the embodiment. FIG. 6 is a diagram showing an example of section setting in the double feed detection process according to the embodiment. FIG. 7 is a diagram showing an example of processing in the detection execution section according to the embodiment.

The start of FIG. 4 is the time when the print job is started. For example, it is the time to start a copy job or a print job. In the case of a copy job, it is the time when the start button of the operation panel 4 is operated. In the case of a print job, it is the time when the print data is received from the computer 200. Multiple jobs may be executed in succession. In this case, the process of FIG. 4 is executed for each page.

First, the control unit 1 recognizes the size and type (thickness) of the paper used for printing (step # 11). The size and type of paper are set in advance on the operation panel 4. The size of the paper can be selected from the standard sizes. The thickness can be selected from multiple stages. FIG. 5 shows an example of the paper type classification table L1. The basis weight (grams / square meter) in FIG. 5 indicates the weight of paper per square meter. For example, office paper that is generally distributed is plain paper. Envelopes and postcards are thick paper 1 or thick paper 2. The user selects a paper type according to the paper loaded in the paper cassette 61. The operation panel 4 accepts the paper size and selection from four stages (types) of thin paper, plain paper, thick paper 1, and thick paper 2.

The control unit 1 stores the paper size and type set on the operation panel 4 in the storage unit 2. The control unit 1 recognizes the size and type of paper by referring to the data of the storage unit 2. The paper cassette 61 may be provided with a sensor for detecting the size and thickness. In this case, the control unit 1 recognizes the size and type of paper based on the outputs of these sensors.

The control unit 1 determines the paper transport speed (step # 12). For example, as the paper transport speed, the first transport speed (normal transport speed) and the second transport speed are predetermined. For example, the second transport speed is ½ of the first transport speed. The operation panel 4 accepts the selection of the transport speed. At the time of printing, the control unit 1 transfers the paper at the selected paper conveying speed.

Next, the control unit 1 sets the start time and end time of the detection section T0 by the double feed detection unit 9 (step # 13). The start time and end time of the detection section T0 are set as the time from the predetermined timing start time P1.

The storage unit 2 stores the first section setting data D1 (see FIG. 1). The first section setting data D1 is data in which the start time and the end time of the detection section T0 are defined for each pattern of the combination of the paper transport speed and the paper size. The control unit 1 sets the start time and the end time of the detection section T0 based on the first section setting data D1.

For example, in the first section setting data D1, the start time when the paper is conveyed at the first transfer speed is defined. For example, the time obtained by dividing the distance from the paper feed unit 6 (the position of the downstream end of the paper cassette 61 in the paper transport direction) to the installation position of the ultrasonic sensor 91 by the first transport speed is the start time of the detection section T0. Is defined as. Further, in the first section setting data D1, the end time when the paper is conveyed at the first transfer speed is also defined. For example, the time obtained by adding the time obtained by dividing the length of the paper in the transport direction by the first transport speed to the start time is defined as the end time of the detection section T0. The length in the transport direction differs depending on the paper size. Therefore, the end time of the detection section T0 is determined for each paper size.

Further, for example, in the first section setting data D1, the start time when the paper is conveyed at the second transfer speed is defined. For example, the time obtained by dividing the distance from the paper feed unit 6 (the position of the downstream end of the paper cassette 61 in the paper transport direction) to the installation position of the ultrasonic sensor 91 by the second transport speed is the start time of the detection section T0. Is defined as. Further, in the first section setting data D1, the end time when the paper is conveyed at the second transfer speed is also defined. For example, the time obtained by adding the time obtained by dividing the length of the paper in the transport direction by the second transport speed to the start time is defined as the end time of the detection section T0. The length in the transport direction differs depending on the paper size. Therefore, the end time of the detection section T0 is determined for each paper size.

Next, the control unit 1 sets a detection execution section and a detection skip section in the detection section T0 (step # 14). In other words, the control unit 1 classifies the time in the detection section T0 into either a detection execution section or a detection skip section. In the detection execution section, the control unit 1 determines whether or not double feeding has occurred based on the detection voltage V1. In the detection skip section, the control unit 1 does not determine whether or not double feed has occurred based on the detection voltage V1.

The storage unit 2 stores the second section setting data D2 (see FIG. 1). The second section setting data D2 is data in which the start time and the end time of the detection skip section are defined for each pattern of the combination of the paper transport speed, the paper size, and the paper type. The time zone that is not the detection skip section is the detection execution section. The second section setting data D2 may be data in which the start time and the end time of the detection execution section are defined for each pattern of the combination of the paper transport speed, the paper size, and the paper type. In this case, the time zone other than the detection execution section is the detection skip section. Details of the setting of the detection execution section and the detection skip section will be described later.

FIG. 6 is a diagram showing an example of a detection execution section and a detection skip section set in the detection section T0. The arrow at the top of FIG. 6 indicates the entire detection section T0. In FIG. 6, the time zone of the shaded rectangle is the detection execution section. The time zone of the white rectangle is the detection skip section.

Here, the control unit 1 does not include the start time and the end time of the detection section T0 in the detection skip section. The control unit 1 always sets the detection execution section from the start time to the elapse of the predetermined time. Further, the control unit 1 always sets the period from the time retroactive to the end time to the end time as the detection execution section. This makes it possible to detect the accompanying double feed. The accompanying double feed is a double feed in which the rear end portion of the preceding paper and the front end portion of the next paper overlap. If the start time and end time of the detection section T0 are included in the detection skip section, it may not be possible to detect the accompanying double feed.

Then, the control unit 1 starts the paper transport operation and the timekeeping (step # 15). When the paper transfer operation is started, the control unit 1 starts the rotation of the paper feed motor 62 and the transfer motor 70. As a result, paper feeding by the paper feeding unit 6 and feeding by the paper feeding unit 7 are started. Further, for timekeeping, the control unit 1 includes a timekeeping circuit 12 (see FIG. 1). The printing operation and the timing start time in step # 15 are the predetermined timing start time P1 described above.

The processing within the detection section T0 will be described with reference to FIG. 7. The control unit 1 alternately performs the first process and the second process in the detection execution section. However, when the detection execution section is reached, the process can be started from the first process. The time for performing the first process is predetermined. Further, the time for performing the second processing within the detection execution section is predetermined.

The first process includes a process of charging the charge circuit 94 with an electric charge. When performing the first process, the control unit 1 turns off the switch unit 95. Further, the control unit 1 includes a process of determining whether or not double feed has occurred based on the detection voltage V1 in the first process. The control unit 1 recognizes (samples) the magnitude of the detection voltage V1 a plurality of times during the period in which the first process is performed. For example, the control unit 1 recognizes the magnitude of the detection voltage V1 10 times in a predetermined cycle.

The control unit 1 determines whether or not double feeding has occurred based on the magnitude of the recognized detection voltage V1. For example, the control unit 1 obtains a determination numerical value based on the detection voltage V1 acquired a plurality of times. For example, the control unit 1 excludes the minimum value and the maximum value of the detection voltage V1 acquired during the execution period of one first process. The control unit 1 obtains an average value of the magnitudes of the remaining detection voltage V1. The control unit 1 determines whether or not the obtained average value is equal to or less than a predetermined threshold value TH. When the obtained average value exceeds the threshold value TH, the control unit 1 determines that double feeding has not occurred. When the obtained average value is equal to or less than the threshold value TH, the control unit 1 determines that double feed has occurred.

When the double feed occurs, the amount (intensity) of the ultrasonic wave received by the receiving unit 93 decreases as compared with the case where the double feed does not occur. The threshold value TH is determined based on the magnitude of the detection voltage V1 when double feed occurs. For example, the experiment is repeated a plurality of times to obtain the minimum value of the average value of the detection voltage V1 when double feeding does not occur. The threshold TH can be set to a value smaller than the minimum value of the average value.

On the other hand, the second process is a process of discharging the electric charge of the charge circuit 94. The control unit 1 turns on the switch unit 95 during the period in which the second process is performed. The control unit 1 continues discharging the charge circuit 94 for a certain period of time. The control unit 1 keeps the switch unit 95 in the ON state until the charge of the capacitor of the charge circuit 94 becomes zero (until the ground level is reached). The time for performing the second treatment is, for example, several tens to several hundreds μs or more (for example, 100 μs). When the time for performing the second process has elapsed, the control unit 1 starts a new first process.

Here, the control unit 1 starts the first process from the start time of the detection execution section. As shown in FIG. 7, the control unit 1 starts the first process at the same time as the detection skip section ends. Therefore, the control unit 1 may maintain the switch unit 95 in the ON state (the state in which the charge circuit 94 is discharged) during the detection skip section.

The control unit 1 waits for the lapse of time from the timing start time P1 to the start time of the detection section T0 (step # 16). When the start time is reached, the control unit 1 starts inputting a pulse to the transmission unit 92. As a result, the transmission unit 92 starts transmitting ultrasonic waves (step # 17).

Further, the control unit 1 confirms whether or not double feed has occurred (whether the average value is equal to or less than the threshold value TH) (step # 18). When double feeding occurs (Yes in step # 18), the control unit 1 stops the paper transport operation (step # 19). The control unit 1 also ends the input of the pulse (transmission of ultrasonic waves) to the transmission unit 92. Then, this flow ends (end).

When the double feed has not occurred (No in step # 18), the control unit 1 confirms whether or not the detection section T0 has ended (step # 110). When the detection section T0 ends (when the end time of the detection section T0 is reached, Yes in step # 110), this flow ends (end). With the end of the detection section T0, the control unit 1 may end the input of the pulse (transmission of ultrasonic waves) to the transmission unit 92. When the detection section T0 is still in progress (No in step # 110), the flow returns to step # 18.

(Setting of detection skip section)
Next, an example of setting the detection skip section according to the embodiment will be described with reference to FIGS. 6 and 8 to 11. 8 to 10 are views showing an example of a collision of the tips of paper in the multifunction device 100 according to the embodiment. FIG. 11 is a diagram showing an example of a collision at the rear end of the paper in the multifunction device 100 according to the embodiment.

The detection skip section is a section in which the detection voltage V1 drops due to the vibration applied to the transport paper. In other words, the detection skip section is a section in which a decrease in the detection voltage V1 due to vibration may be erroneously detected as a double feed occurrence. The control unit 1 sets a detection skip section based on the time when vibration is applied to the paper. The second section setting data D2 is defined based on the time when vibration is applied to the paper.

There are multiple factors and points in time when the paper is vibrated while passing through the ultrasonic sensor 91. Therefore, a plurality of detection skip sections can be provided in the detection section T0. The control unit 1 sets one or a plurality of four types of the first detection skip section T1, the second detection skip section T2, the third detection skip section T3, and the fourth detection skip section T4.

The first detection skip section T1 is a detection skip section for dealing with a collision of the conveyed paper at the downstream end (paper tip) in the paper conveying direction with the conveying guide 74. The control unit 1 sets the time point at which the tip of the paper collides with the transport guide 74 as the start time of the first detection skip section T1.

FIG. 8 shows an example of a collision of the paper tip with the transport guide 74. When the tip of the paper collides with the transport guide 74, a large vibration is transmitted to the paper. The vibration of the paper cancels the ultrasonic waves emitted from the transmitter 92. Of the detection skip sections shown in FIG. 6, the first one is the first detection skip section T1. The start time of the first detection skip section T1 is also the end time of the immediately preceding detection execution section.

For example, the time obtained by dividing the distance from the paper feed unit 6 to the transport guide 74 by the paper transport speed may be set as the start time of the first detection skip section T1. Further, the start time of the first detection skip section T1 may be determined by an experiment. In this case, the time from the timing start time P1 until the tip of the paper collides with the transport guide 74 is measured a plurality of times. The average value of the measured times may be used as the start time of the first detection skip section T1. The control unit 1 starts the first detection skip section T1 when the start time determined from the timekeeping start time P1 has elapsed. In the second section setting data D2, the start time of the first detection skip section T1 is determined for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness).

The end time of the first detection skip section T1 is appropriately determined. For each pattern of combination of paper size, paper transport speed, and paper type (thickness), the time for the detection voltage V1 to recover to the extent that false positives do not occur after the paper tip collides with the transport guide 74 is measured in advance. Be done. For example, after the collision, the time until the value of the detection voltage V1 records the threshold value TH is measured. Based on the measured time, the end time (time interval from the start time to the end time) of the first detection skip section T1 can be determined. The control unit 1 ends the first detection skip section T1 when the end time determined from the timekeeping start time P1 has elapsed. The second section setting data D2 includes the end time of the first detection skip section T1 (start time of the new detection execution section) for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness). Is also determined.

The second detection skip section T2 is for dealing with the rubbing of the conveyed paper at the downstream end (paper tip) in the paper conveying direction with respect to the conveying guide 74 and the collision with the conveying rotating body 71 (intermediate roller pair 72). It is a detection skip section of. The transport rotating body 71 is a rotating body provided on the downstream side in the paper transport direction with respect to the ultrasonic sensor 91. The control unit 1 includes a part of the time zone in which the transfer paper is rubbed against the transfer guide 74 in the detection skip section. Further, the control unit 1 sets the time point at which the tip of the paper collides with the rotating body 71 for transport as the start time of the detection skip section.

FIG. 9 shows an example of the rubbing of the paper on the transport guide 74 and the collision with the intermediate roller pair 72. The vibration due to the rubbing between the paper and the transport guide 74 is smaller than when the tip of the paper collides. However, the vibration due to the rubbing between the paper and the transport guide 74 is continuous. When the tip of the paper collides with the rotating body 71 for transportation in a rubbing state, the vibration of the paper may increase. Of the detection skip sections shown in FIG. 6, the second one from the beginning is the second detection skip section T2. The start time of the second detection skip section T2 is also the end time of the immediately preceding detection execution section.

For example, the time obtained by dividing the distance from the paper feed unit 6 to the intermediate roller pair 72 by the paper transport speed (intermediate roller pair arrival time) is obtained. The obtained time may be used as the start time of the second detection skip section T2. Alternatively, in consideration of rubbing, a time shorter than the obtained time may be set as the start time of the second detection skip section T2. The control unit 1 starts the second detection skip section T2 when the start time determined from the timekeeping start time P1 has elapsed. In the second section setting data D2, the start time of the second detection skip section T2 is determined for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness).

The end time of the second detection skip section T2 is appropriately determined. The end time is determined for each pattern of the combination of paper size, paper transport speed, and paper type (thickness). For example, after the start of the second detection skip section T2, the time until the value of the detection voltage V1 records the threshold value TH is measured. Based on the measured time, the end time (time interval from the start time to the end time) of the second detection skip section T2 can be determined. The control unit 1 ends the second detection skip section T2 when the end time determined from the timekeeping start time P1 has elapsed. The second section setting data D2 includes the end time of the second detection skip section T2 (start time of the new detection execution section) for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness). Is also determined.

The third detection skip section T3 is a detection skip section for dealing with a collision of the transport paper at the downstream end (paper tip) in the paper transport direction with the transport rotating body 71 (resist roller pair 73). The resist roller pair 73 is a rotating body provided on the downstream side in the paper transport direction with respect to the ultrasonic sensor 91. The control unit 1 sets the time point at which the tip of the paper collides with the resist roller pair 73 as the start time of the detection skip section. The start time of the third detection skip section T3 is also the end time of the immediately preceding detection execution section.

FIG. 10 shows an example of the collision of the paper tip with the resist roller pair 73. The resist roller pair 73 is stopped when the paper tip is reached. The tip of the paper is abutted against the resist roller pair 73. Therefore, when the tip of the paper collides with the resist roller pair 73, a large vibration may be transmitted to the paper. The vibration of the paper cancels the ultrasonic waves emitted from the transmitter 92. Of the detection skip sections shown in FIG. 6, the third one from the beginning is the third detection skip section T3. The start time of the third detection skip section T3 is also the end time of the immediately preceding detection execution section.

For example, the time obtained by dividing the distance from the paper feed unit 6 to the resist roller pair 73 by the paper transport speed (resist arrival time) is obtained. The obtained time may be used as the start time of the third detection skip section T3. The control unit 1 starts the third detection skip section T3 when the start time determined from the timekeeping start time P1 has elapsed. In the second section setting data D2, the start time of the third detection skip section T3 is determined for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness).

The end time of the third detection skip section T3 is appropriately determined. The end time is determined for each pattern of the combination of paper size, paper transport speed, and paper type (thickness). For example, after the start of the third detection skip section T3, the time until the value of the detection voltage V1 records the threshold value TH is measured. Based on the measured time, the end time (time interval from the start time to the end time) of the third detection skip section T3 can be determined. The control unit 1 ends the third detection skip section T3 when the end time determined from the timekeeping start time P1 has elapsed. The second section setting data D2 includes the end time of the third detection skip section T3 (start time of the new detection execution section) for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness). Is also determined.

The rear end of the paper may be released from the end of the transport guide 74 and bounce. Due to this bounce, the rear edge of the paper may collide with the transport guide 74. The fourth detection skip section T4 is a detection skip section for dealing with a collision of the conveyed paper at the upstream end (rear end of the paper) in the paper conveying direction with the conveying guide 74. The control unit 1 sets the start time of the detection skip section as the time point at which the upstream end portion of the transport paper in the paper transport direction collides with the transport guide 74 by being released from the end portion of the transport guide 74 and bouncing.

The collision between the bounce and the rear edge of the paper will be described with reference to FIG. In the multifunction device 100, the transport path is curved. As shown in the left figure of FIG. 11, in the multifunction device 100, the paper is conveyed in a bent state so that the right side is convex. In the multifunction device 100, the end portion of the transport guide 74 is located on the upstream side in the paper transport direction with respect to the ultrasonic sensor 91. When the rear edge of the paper comes off, there is no wall to suppress the bending (elasticity) of the paper. As a result, the rear edge of the paper may bounce as shown in the right figure of FIG. The rear edge of the bounced paper may collide with the transport guide 74. When the rear end of the paper collides with the transport guide 74, a large vibration is transmitted to the paper. The vibration of the paper cancels the ultrasonic waves emitted from the transmitter 92. Of the detection skip sections shown in FIG. 6, the last one is the fourth detection skip section T4. The start time of the fourth detection skip section T4 is also the end time of the immediately preceding detection execution section.

For example, the time obtained by dividing the distance from the paper feed unit 6 to the end of the transfer guide 74 by the paper transfer speed is obtained. The obtained time may be used as the start time of the fourth detection skip section T4. Further, the start time of the fourth detection skip section T4 may be determined by an experiment. In this case, the time from the timing start time P1 until the rear end of the paper collides with the transport guide 74 is measured a plurality of times. The average value of the time measured from the time counting start time P1 may be used as the start time of the fourth detection skip section T4. The control unit 1 starts the fourth detection skip section T4 when the start time determined from the timekeeping start time P1 has elapsed. In the second section setting data D2, the start time of the fourth detection skip section T4 is determined for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness).

The end time of the fourth detection skip section T4 is also appropriately determined. For each pattern of combination of paper size, paper transport speed, and paper type (thickness), the time for the detection voltage V1 to recover to the extent that erroneous detection does not occur after the collision with the transport guide 74 at the rear end of the paper is in advance. It is measured. For example, after the collision, the time until the average value of the detection voltage V1 obtained during the fourth processing period recovers to a predetermined recovery amount is measured. Based on the measured time, the end time (time interval from the start time to the end time) of the fourth detection skip section T4 can be determined. The control unit 1 ends the fourth detection skip section T4 when the end time determined from the timing start time P1 has elapsed. The second section setting data D2 includes the end time of the fourth detection skip section T4 (start time of the new detection execution section) for each pattern of the combination of the paper size, the paper transport speed, and the paper type (thickness). Is also determined.

(Setting of detection execution section and detection skip section according to paper size)
Next, an example of setting the detection execution section and the detection skip section according to the paper size will be described with reference to FIG. 12. FIG. 12 is a diagram showing an example of setting a detection execution section and a detection skip section according to the embodiment.

In the multifunction device 100, there are a plurality of paper sizes that can be used. The time during which vibration is applied to the paper varies depending on the paper size. Therefore, the detection execution section and the detection skip section may be set according to the paper size.

FIG. 12 shows an example of setting the detection skip section according to the paper size. In FIG. 12,
The upper figure shows an example of the detection section T0 when the paper having the length in the paper transport direction having the length of the short side of A4 is conveyed. The lower figure of FIG. 12 shows an example of the detection section T0 when the paper having the length in the paper transport direction having the length of the long side of A3 is conveyed. The length of the long side of A3 is twice the length of the short side of A4.

When the paper transport speed is the same, the time point at which the tip of the paper collides with the transport guide 74 or the transport rotating body 71 does not change even if the paper size is different. Therefore, when the paper transport speed and the paper type are the same, the control unit 1 may set the start time points of the first detection skip section T1, the second detection skip section T2, and the third detection skip section T3 to be the same.

On the other hand, when the paper transport speed is the same and the paper size is different, the collision time point of the rear end of the paper changes. This is because the time points of passing through the end of the transport guide 74 are different. Therefore, when the paper transport speed and the paper type are the same, the control unit 1 may set the start time of the fourth detection skip section T4 as the time according to the paper size. In this way, the control unit 1 may set the detection execution section and the detection skip section according to the size of the paper. The second section setting data D2 may be defined so that the start time points of the detection skip sections are different in the patterns of combinations in which the paper transport speed and the paper type are the same but the paper sizes are different.

(Setting of detection execution section and detection skip section according to the paper type)
Next, an example of setting the detection execution section and the detection skip section according to the paper type will be described with reference to FIG. FIG. 13 is a diagram showing an example of setting a detection execution section and a detection skip section according to the embodiment.

In the multifunction device 100, paper of various thicknesses can be used. The ease with which vibration is transmitted, the magnitude of vibration, and the ease with which it bounces differ depending on the thickness of the paper. Therefore, the detection execution section and the detection skip section may be set according to the paper type (paper thickness).

FIG. 13 shows an example of setting the detection skip section according to the paper type. In FIG. 13,
The uppermost row shows an example of the thin paper detection section T0, the second row shows the plain paper detection section T0, the third row shows the thick paper 1 detection section T0, and the final row shows an example of the thick paper 2 detection section T0.

When the paper transport speed and paper size are the same, even if the thickness is different, the point at which collision or bounce occurs is basically the same. On the other hand, the ease of transmission (rigidity), the ease of bouncing (elasticity), and the ease of propagation of vibration differ depending on the thickness. The length of the period (vibration attenuation rate) that may be falsely detected as double feeding differs depending on the thickness of the paper. In general, the thinner the paper, the faster the vibration due to impact will be damped. Therefore, when the size of the transport paper and the transport speed are the same, the control unit 1 may lengthen the detection skip section as the transport paper is thicker. Further, the control unit 1 may shorten the detection skip section as the conveyed paper becomes thinner. As described above, the second section setting data D2 may be defined so that the lengths of the detection skip sections are different in the patterns of combinations in which the paper transport speed and the paper size are the same but the paper types are different. ..

FIG. 13 shows an example in which the detection skip section is not provided on the thin paper. Further, FIG. 13 shows an example in which only the first detection skip section T1 is provided on plain paper. FIG. 13 shows an example in which the number of detection skip sections is increased and the total time of the detection skip sections is increased in the thick paper 1 as compared with the thin paper and the plain paper. FIG. 13 shows an example in which the number of detection skip sections of the thick paper 2 is increased and the total time of the detection skip sections is increased as compared with the thin paper, the plain paper, and the thick paper 1. As described above, the control unit 1 may shorten the detection skip section as the paper is thinner and lengthen the detection skip section as the paper is thicker.

(Setting of detection execution section and detection skip section according to the transport speed)
Next, an example of setting the detection execution section and the detection skip section according to the transport speed will be described with reference to FIG. FIG. 14 is a diagram showing an example of setting a detection execution section and a detection skip section according to the embodiment.

The paper transfer speed of the multifunction device 100 is multi-step. Generally, the faster the speed, the greater the impact of a collision. Therefore, the faster the paper transport speed, the greater the impact on the paper when the front and rear ends collide. Therefore, the detection execution section and the detection skip section may be set according to the paper size.

FIG. 14 shows an example of setting the detection skip section according to the transport speed. In FIG. 14, the upper figure shows an example of the detection section T0 in the case of the first transport speed (normal speed). The lower figure of FIG. 14 shows an example of the detection section T0 in the case of the second transport speed (half speed of the normal speed).

On the other hand, even if the paper size is the same, if the paper transport speed is different, the time when the edges of the paper collide and the magnitude of vibration at the time of collision change. Therefore, when the type and size of the conveyed paper are the same, the control unit 1 increases the ratio of the detection skip section in the detection section T0 as the paper conveying speed is faster. On the other hand, the control unit 1 reduces the ratio of the detection skip section in the detection section T0 as the paper transport speed becomes slower. The second section setting data D2 so that the ratio of the total time of the detection skip section to the total length of the detection section T0 is different in the combination pattern in which the paper size and the paper type are the same but the paper transport speeds are different. May be defined.

The paper may vibrate due to a collision with the transport guide 74 or the transport rotating body 71. Vibrations can propagate through the paper, canceling or diffusing the ultrasonic waves. The impact (vibration) on the paper may reduce the ultrasonic waves that reach the receiving unit 93. Even if only one sheet of paper is transported, the ultrasonic reception level (intensity) may drop to a level close to that at the time of double feeding. As a result, the occurrence of double feed may be erroneously detected. Therefore, the multifunction device 100 (paper transport device) according to the embodiment includes a paper feed unit 6, a transport rotating body 71, a transport guide 74, a double feed detection unit 9, and a control unit 1. The paper feed unit 6 accommodates the paper and supplies the paper. The transport rotating body 71 transports paper. The transport guide 74 guides the transport paper. The double feed detection unit 9 includes an ultrasonic sensor 91 and a charge circuit 94. The detection voltage V1, which is the output of the double feed detection unit 9, is input to the control unit 1. The ultrasonic sensor 91 includes a transmitting unit 92 and a receiving unit 93. The transmission unit 92 transmits ultrasonic waves. The receiving unit 93 outputs a charge according to the level of the received ultrasonic wave. The transmitting unit 92 and the receiving unit 93 are provided so that the paper is conveyed on and between the paper conveying path. The charge circuit 94 outputs a voltage charged with a charge output by the receiving unit 93 as the detection voltage V1. The control unit 1 sets a detection section T0 for transmitting ultrasonic waves to the transmission unit for each transfer paper. In the detection section T0, the control unit 1 causes the transmission unit 92 to transmit ultrasonic waves having a predetermined period. The control unit 1 sets a detection execution section and a detection skip section in the detection section T0. The control unit 1 determines whether or not double feeding occurs in the detection execution section based on the detection voltage V1. The control unit 1 does not determine whether or not double feed has occurred based on the detection voltage V1 in the detection skip section. The control unit 1 sets a detection skip section based on the time when vibration is applied to the conveyed paper.

According to this configuration, it is possible not to determine whether or not the double feed has occurred during the period (detection skip section) in which the false detection of the double feed may occur due to the collision or rubbing against the member. Even if the ultrasonic waves reaching the receiving unit 93 are temporarily attenuated due to the vibration of the paper, it is possible to prevent erroneous detection of double feeding. It is possible to accurately determine whether or not double feeding has occurred while considering the vibration applied to the paper.

The double feed detection unit 9 includes a switch unit 95 for removing the electric charge of the charge circuit 94. The control unit 1 alternately performs the first process and the second process in the detection execution section. When performing the first process, the control unit 1 charges the charge circuit 94 with the switch unit 95 in the OFF state, and acquires the detection voltage V1. When performing the second process, the control unit 1 discharges the charge circuit 94 with the switch unit 95 turned on. The control unit 1 sets the switch unit 95 to the ON state before the time when the detection skip section is switched to the detection execution section, and completes the discharge of the charge circuit 94. The first process is started when the detection execution section is reached. The start time of the first process (the end time of the second process, the end time of discharging the charge circuit 94) and the start time of the detection execution section can be combined. The period during which the charge circuit 94 is discharged does not straddle the detection execution section. It is possible to start determining whether or not double feed has occurred according to the start time of the detection execution section. There are no omissions or delays in the detection of double feed.

The control unit 1 sets the start time of the detection skip section as the time point at which the downstream end portion of the transport paper in the paper transport direction collides with the transport guide 74. The downstream end (paper tip) in the paper transport direction may hit the transport guide 74. A time zone in which false detection of double feed may occur due to a collision can be set as a detection skip section. It is possible to eliminate the false detection of double feed due to the collision of the downstream end.

The control unit 1 includes a part of the time zone in which the transfer paper is rubbed against the transfer guide 74 in the detection skip section. False detection of double feed may occur due to vibration caused by rubbing between the transport paper and the transport guide 74. A time zone in which false detection of double feed may occur due to rubbing can be set as a detection skip section. It is possible to eliminate false detection of double feeding due to rubbing.

The control unit 1 sets the start time of the detection skip section as the time point at which the downstream end portion of the transport paper in the paper transport direction collides with the transport rotating body 71 on the downstream side in the paper transport direction with respect to the ultrasonic sensor 91. The downstream end (paper tip) in the paper transport direction may hit the transport rotating body 71 (roller). A time zone in which false detection of double feed may occur due to this collision can be set as a detection skip section. It is possible to eliminate the false detection of double feed due to the collision of the downstream end.

The control unit 1 sets the start time of the detection skip section as the time point at which the upstream end portion of the transport paper in the paper transport direction collides with the transport guide 74 by being released from the end portion of the transport guide 74 and bouncing. When the upstream end (rear end of the paper) in the paper transport direction is separated from the end of the transport guide 74, the elasticity of the paper causes the paper to vigorously hit the transport guide 74. A time zone in which erroneous detection of double feed may occur due to a collision at the upstream end can be set as a detection skip section. It is possible to eliminate the false detection of double feed due to the collision of the downstream end.

The control unit 1 recognizes the size of the conveyed paper. The control unit 1 sets a detection execution section and a detection skip section according to the size of the paper. The detection execution section and the detection skip section can be appropriately set according to the size of the paper.

When the size of the transport paper and the transport speed are the same, the thinner the transport paper, the smaller the vibration when it collides with the transport guide 74 or the transport rotating body 71. Because of the tendency to bend, thin paper is more likely to absorb vibrations than thick paper. In addition, the thinner the transport paper, the easier it is for ultrasonic waves to pass through. Even if vibration is applied, the thinner the paper, the shorter the time that vibration remains so that false detection of double feeding occurs. Therefore, the control unit 1 recognizes the type of the conveyed paper. When the size of the transport paper and the transport speed are the same, the control unit 1 lengthens the detection skip section as the transport paper is thicker, and shortens the detection skip section as the transport paper is thinner. The detection skip section can be set according to the thickness of the paper. Specifically, the detection skip section of thin paper can be made shorter than the detection skip section of thick paper. The detection execution section can be made as long as possible. The detection skip section of thick paper can be made longer than the detection skip section of thin paper. False detection of double feed can be eliminated.

When colliding at high speed, the vibration of the paper is larger than when colliding at low speed. It is preferable that the faster the transport speed, the higher the ratio of the detection skip section in the detection section T0. Therefore, when the type and size of the conveyed paper are the same, the control unit 1 increases the ratio of the detection skip section in the detection section T0 as the paper conveying speed is faster, and increases the ratio of the detection skip section in the detection section T0 as the paper conveying speed is slower. Decrease the ratio of the detection skip section in. The detection skip section can be set according to the paper transport speed. False detection of double feed can be reduced regardless of the speed of transport.

If the detection execution section is too short, it may not be possible to properly determine whether or not double feed occurs. Therefore, when the detection execution section between the detection skip section and the detection skip section is shorter than the predetermined minimum time, the control unit 1 changes the detection execution section shorter than the minimum time to the detection skip section, and a plurality of detection execution sections. Integrate detection skip sections. It is possible to change the detection execution section that is too short to the detection skip section. It is possible to replace the detection execution section that may not be properly determined with the detection skip section. It is possible to eliminate false detection of double feed occurrence.

The control unit 1 does not include the start time and end time of the detection section T0 in the detection skip section. It is possible to accurately detect the occurrence of double feed in which the edges of the paper overlap (double feed with accompanying paper, double feed in which the overlapping portion is short).

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the gist of the invention.

The present invention can be used for a paper transport device.

100 Multifunction device (paper transfer device) 1 Control unit 6 Paper feed unit 71 Transport rotating body 74 Transport guide 9 Double feed detector 91 Ultrasonic sensor 92 Transmitter 93 Receiver 94 Charge circuit 95 Switch section T0 Detection section V1 detection Voltage

Claims (9)

A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit is a paper transport device characterized in that a time point at which a downstream end portion of the transport paper in the paper transport direction collides with the transport guide is set as a start time of the detection skip section . The paper transport device according to claim 1 , wherein the control unit includes a part of a time zone in which the transport paper is rubbed against the transport guide in the detection skip section. The control unit sets the start time of the detection skip section as the time point at which the downstream end portion of the transport paper in the paper transport direction collides with the transport rotating body on the downstream side in the paper transport direction with respect to the ultrasonic sensor. The paper transport device according to claim 1 or 2 , wherein the paper transport device is characterized.
A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit sets the start time of the detection skip section as the time point at which the upstream end portion of the transport paper in the paper transport direction collides with the transport guide by being released from the end portion of the transport guide and bouncing. A paper transfer device characterized by. The control unit
Recognize the size of the carrier paper and
The paper transport device according to any one of claims 1 to 4 , wherein the detection execution section and the detection skip section are set according to the size of the paper. A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit
Recognize the type of transport paper
When the size of the transport paper and the transport speed are the same, the paper transport device is characterized in that the thicker the transport paper, the longer the detection skip section, and the thinner the transport paper, the shorter the detection skip section . A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit
When the type and size of the conveyed paper are the same, the faster the paper conveying speed is, the larger the ratio of the detection skip section is in the detection section, and the slower the paper conveying speed is, the more the detection skip is in the detection section. A paper transport device characterized by reducing the ratio of sections . A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit
When the detection execution section between the detection skip section and the detection skip section is shorter than a predetermined minimum time, the detection execution section shorter than the minimum time is changed to the detection skip section, and the plurality of the detection skip sections are described. A paper transfer device characterized by integrating detection skip sections . A paper feed unit that stores and supplies paper,
A rotating body for transporting paper and
A transport guide that guides the transport paper and
A double feed detector including an ultrasonic sensor and a charge circuit,
A control unit for inputting a detection voltage, which is an output of the double feed detection unit, is provided.
The ultrasonic sensor includes a transmitter and a receiver, and includes a transmitter and a receiver.
The transmitter emits ultrasonic waves and emits ultrasonic waves.
The receiving unit outputs an electric charge according to the level of the received ultrasonic wave, and outputs the electric charge.
The transmitting unit and the receiving unit are provided so as to transport paper on and between the paper transport paths.
The charge circuit outputs a voltage charged with a charge output by the receiving unit as the detection voltage.
The control unit
Set the detection section to transmit ultrasonic waves to the transmitter for each transport paper.
In the detection section, ultrasonic waves having a predetermined period are transmitted to the transmission unit.
A detection execution section and a detection skip section are set in the detection section, and the detection skip section is set.
In the detection execution section, it is determined whether or not double feeding occurs based on the detection voltage, and it is determined.
In the detection skip section, it is not determined whether or not double feed has occurred based on the detection voltage, and it is not determined.
The detection skip section is set based on the time when vibration is applied to the conveyed paper .
The control unit is a paper transport device, characterized in that the start time and end time of the detection section are not included in the detection skip section .

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